Class PatternCaptureGroupTokenFilter

CaptureGroup uses .NET regexes to emit multiple tokens - one for each capture group in one or more patterns.

For example, a pattern like:

"(https?://([a-zA-Z-_0-9.]+))"

when matched against the string "http://www.foo.com/index"; would return the tokens "https://www.foo.com" and "www.foo.com".

If none of the patterns match, or if preserveOriginal is true, the original token will be preserved.

Each pattern is matched as often as it can be, so the pattern "(...)", when matched against "abcdefghi" would produce ["abc","def","ghi"]

A camelCaseFilter could be written as:

  "([A-Z]{2,})",                                 
  "(?<![A-Z])([A-Z][a-z]+)",                     
  "(?:^|\\b|(?<=[0-9_])|(?<=[A-Z]{2}))([a-z]+)", 
  "([0-9]+)"

plus if Lucene.Net.Analysis.Pattern.PatternCaptureGroupTokenFilter.preserveOriginal is true, it would also return camelCaseFilter